EXPLANATION OF PLATE LVIII. 



Figs. 1-3. SPIRIFER MORTONANUS Miller p. 366 



1-2. Views of two pedicle valves. (W. M., No. 13328.) 3. Pos- 

 terior view of a nearly complete specimen. (W. M.. No. 13521.) 

 Crawfordsi'illc Beds, Crawfordsiillc, Indiana. 



Figs. 4-8. BRACHYTH YRIS GURLEYI n. sp p. 377 



Pedicle, brachial, anterior, posterior and lateral views of the 

 holotype. (W. M., No. 7550.) 

 Salon limestone, Indiana. 



Figs. 9-20. BRACK YTHYRIS PECULIARIS (Shumard) p. 381 



9-12. Pedicle, brachial, anterior and lateral views of a very per- 

 fect specimen. 13-16. Pedicle, brachial, posterior and lateral 

 views of another specimen. (W. M., No. 9662.) 



Chouteau limestone, Choutcau Springs, Missouri. 

 17-20. Pedicle, brachial, anterior and posterior views of a very 

 narrow specimen. (W. M., No. 7941.) 



Chouteau limestone, Pcttis County, Missouri. 



132 



